Catheters used in the medical field and the like, such as vascular catheters and urethral catheters for urethral catheterization, and the like are inserted into blood vessels, digestive tracts, tracheae, bile ducts, or ureters and used in aqueous solutions such as blood or body fluids. They are thus required to be able to be smoothly inserted without damaging tissues.
In this context, a low friction lubricant is applied to the surface of a catheter, or the surface is coated with a lubricant layer, before use (see Patent Literatures 1 to 3). However, these methods have drawbacks in that the surfaces thus formed have insufficient lubricity, and that since the lubricants are not chemically fixed on the surfaces of catheters, they are, for example, separated or peeled during the movement within a vessel or tube, so that the lubricity is reduced.